Mechanical behavior of TPS films was characterized by two independent and complementary techniques (tensile tests and quasistatic assays). It is well known that fillers incorporation to TPS
matrixes allows improving mechanical properties of composite materials. Fig. 1 shows stress-strain curves corresponding to TPS and its bionanocomposites containing talc particles determined by
both techniques. As it is observed in the curves obtained by tensile and quasi-static assays, filler addition did not modify stress-strain behavior of TPS, showing a characteristic curve of ductile mate-
rials. Table 1 presents mechanical properties of developed materials. Despite different values were obtained by both techniques, talc addition influence onTPS mechanical performance was similar.
Tensile and quasi-static experiments revealed that the lowest used talc concentration did not affect (p > 0.05) film stiffness. Considering results from quasi-static assays, a stiffness increment of
around 15% was observed for samples with 3% w/w talc concentration. A 5% w/w of talc addition increased Young’s modulus around 68 and 81%, determined by tensile and quasi-static exper-
iments, respectively. Incorporation of 1% w/w talc particles to TPS formulations increased 1.2 times the maximum tensile stress, determined by tensile tests. Both techniques demonstrated that 3
and 5% w/w talc incorporation increased significantly (p < 0.05) TPS yield stress. Well dispersion and distribution of nanoparticles with in the matrix, attributed to good starch-talc compatibility,
allow TPS materials reinforcement (Lim, Lee, & Tay, 2009). Particle-matrix interfacial adhesion could be associated to the edge surfaces which have hydrophilic groups such as -SieOH and -MgeOH
(Chabrol et al., 2010). In addition, Ferrage et al. (2002) reported the presence of electronegative sites on talc tetrahedral sheets propitious to form hydrogen bonds with polypropylene methyl groups.
Similar interaction could be expected for composites based on TPS and talc nanoparticles.